Front row is the main area of concern but there are opportunities in other areas too for some to get their first taste of involvement with the senior national squad, or make returns to the fold.
Vern Cotter named a 37-man this time last year and it is possible that Townsend might go with a few more to give more wiggle room as the opener against Wales in Cardiff on 3 February approaches fast.
It is widely expected that Newcastle’s Jon Welsh will return to the full squad and be in pole position to start in the Welsh capital, with the leading duo of WP Nel and Zander Fagerson set to miss most if not all of the tournament.
Edinburgh’s Simon Berghan is suspended but will be named in the squad as his ban is up the day after the Wales game, while there could be a call for either of both young prospects D’Arcy Rae of Glasgow and Murray McCallum of Edinburgh.
With Ross Ford out long-term and Fraser Brown currently sidelined after suffering numerous head knocks, Stuart McInally will be the main hooker, with back up from the Glasgow pair of George Turner and Pat MacArthur.
The Edinburgh loosehead trio of Al Dickinson, Allan Dell and Darryl Marfo are all currently injured, although there are hopes that the latter two are not long term. That puts Glasgow 24-year-old Jamie Bhatti in the frame for a first Scotland start after three bench appearances in November. Former Glasgow man Gordon Reid, now at London Irish, should also make a comeback.
In the second row, Richie Gray is back playing for Toulouse after missing the autumn with a back problem and will get the call but faces a battle to dislodge the home-based trio of his brother Jonny and the in-form Edinburgh pair of Grant Gilchrist and Ben Toolis.
Ryan Wilson’s ankle injury may open the door to a return for Worcester’s David Denton and it will be interesting to see if Magnus Bradbury has done enough to convince the selectors he is back in international form.
Edinburgh-bound Scarlets flanker John Barclay is likely to remain in post as captain, which brings us to the most intriguing backs position - scrum-half.
Greig Laidlaw is on the injury comeback trail with Clermont and will almost certainly be named in the squad, but may find himself on the bench in Cardiff behind Ali Price, who has seized his chance in the skipper’s absence last year.
Glasgow’s free-scoring young scrum-half George Horne could be given the call, potentially leaving the Edinburgh duo of Sam Hidalgo-Clyne and Nathan Fowles disappointed.
Townsend will have been in talks with Saracens over the fitness of centre Duncan Taylor, who has only played 23 minutes of rugby since his return from injury at the turn of the year.
Harlequins wing Tim Visser was the major omission from Townsend’s autumn Tests squad, with the coach revealing that the prolific ex-Edinburgh man had been tasked with making improvements to his all-round game. Tomorrow we’ll discover if his homework has passed muster.
Questions on Townsend’s confidence in the fitness of star full-back Stuart Hogg, who it is hoped will get a first run out since November this weekend, will be to the fore at tomorrow’s press conference.
Two days before his 21st birthday, there could be an early reason to celebrate for Edinburgh’s No 15 Blair Kinghorn, whose recent form could well have been enough to earn him an invite.